


Tender Flames of the Future

by easternCriminal



Category: Katekyou Hitman Reborn!, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: Crossover, Gen
Language: English
Status: In-Progress
Published: 2018-06-27
Updated: 2018-08-01
Packaged: 2019-05-29 06:22:22
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 12,637
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15067064
Author URL: https://archiveofourown.org/users/easternCriminal/pseuds/easternCriminal
Summary: “I don’t want to be a vigilante, I want to become a real hero, with a hero license and everything. I want to work with the law and not around it.”Tsuna, the heir to the group of vigilantes known as the Vongola, never wanted to be outside the law. Instead, determined to become a hero the right way, with the help of his two best friends at his sides, takes on the task of attending UA and obtaining his license





	1. The Concept

“So Tsuna… what is it you wanted to talk to me about?” Nono adjusted his position to sit forward a little more. They were currently in the Vongola gardens, Timoteo had claimed he was tired of being the stuffy indoors so he had led them to a small spot next to a fountain. There were two benches that faced each other, a small coffee table in the middle with some refreshments on it and flowers growing out a hole in the center.

Gokudera and Yamamoto had been the only ones of his guardians to come. The others were busy with school or life stuff - Lambo had returned to the Bovino family for a short period of time, Ryohei had his studies, Hibari and Murkuro were doing who knows what. Chrome had been busy keeping Chickusa and Ken in check (and fed). So there was just him, his storm, and his rain, sitting on his right and left respectively.

“Yes, I…” Tsuna took a deep breath. “I don’t want to be the Vongola Decimo.” Tsuna closed his eyes, he couldn’t look at his grandpa’s disappointed face.

“I thought Reborn already talked to you about this - if you don’t like the name Vongola Decimo, a simple change to Neo Primo is easy enough.”

“T-that’s not it. I don’t want to be the Neo Primo either.” Nono nodded slowly.

“Well whatever vigilante title you choose I’m sure will be fine, it’s okay to break tradition every now and then. It would still be best to do something that relates back to the Vongola, maintain the united front we have.” Tsuna shook his head.

“I don’t think you understand gra - Nono.” Tsuna bit his lip. “I don’t want to be a vigilante, I want to become a real hero, with a hero license and everything. I want to work with the law and not around it.” There was a tense silence as those present digested the information. The Vongola was a long line of vigilantes, one of the largest groups on the world (especially after their brief period of delving into the mafia world for a while there). To break that cycle would be… unthinkable.

“Of course Tsuna, I wouldn’t ever want to force you into something.” Tsuna breathed out a sigh of relief. “Why don’t you and your guardians stay over the night, we can talk logistics of getting you your hero license in the morning.”

“That sounds great grandpa!”

“In the meantime, if you’ll excuse me, I have some coordinating to work out.” Nono got up from his seat and exited the sitting area, mind already turning ideas over.

“You’re soft on him.” Reborn, of course. The hitman had been aging faster since his curse had released a year ago, but that didn’t mean much. He looked to be somewhere between 4-5 years old now, Verde predicted that they’re somewhat accelerated growth would return to normal once they hit their original age (Timoteo hoped so - no one dared speak of the fear that they would continue to grow older and older until it they died of age far sooner than they should).

“If he doesn’t want to be the next leader of the Vongola he shouldn’t have to be.” Nono replied, and Reborn gave a hum that wasn’t quite approval.

oOo

“You don’t want to become the Vongola, Tenth?” Gokudera turned to Tsuna once Nono was out of sight. Tsuna seemed to shrink slightly in on himself and Gokudera made an effort to relax his shoulders a little bit more and to lean back.

“Being wanted and on the run, having to be so secretive my whole life…” Tsuna shuddered a little bit.

“Well if you’re going to get your hero license than both me and Gokudera will have to as well, right?” Yamamoto gave Tsuna a bright smile and glanced up to meet Hayato’s eyes.

“I thought that went without saying.” Gokudera huffed, swinging his arm around Tsuna’s shoulder. “You and I are going to make the best Superhero duo the world has ever seen!”

“Don’t you mean that Tsuna and I are definitely going be legendary partners?” Yamamoto replied, but the argument had no bite to it - the small smile that graced Tsuna’s face was all they needed.

“You guys are really okay with that?”

“Of course Tenth - wherever you go I’ll follow!” Gokudera gave Tsuna a thumbs up.

“What kind of friends would we be otherwise?” Tsuna relaxed finally and stood, stretching a little.

“Thank you guys, it really means a lot to me.” He glanced around the garden. “I guess we should go and find out where we’ll be sleeping for the night.”

oOo

“After having the night to work things out, Ninth and I have come up with a plan to help you on your course to become a legal hero.” Reborn faced his charge, who was nervously sitting on a couch in one of the many meeting rooms in Vongola mansion. Yamamoto was sitting to his left while Gokudera was on his right, poised over a notepad and already copying down information from Reborn’s planning board he had up on the wall. Nono stood off to the side, leaning on his cane.

“Getting a license at such a young age is difficult - many facilities simply won’t allow it, and the process to even getting considered it extremely difficult.”

“We can do it.” Gokudera said confidently.

“Or we could be smart about this.” Reborn replied. “There are some elite hero course high schools that give their students the opportunity to try out for the license. You may have heard of some of them, such as Yuuei.” Tsuna couldn’t help the gasp that escaped his mouth. Yamamoto sprung forward from his reclined position, eyes sharp. Even Gokudera looked somewhat shaken.

“R-Reborn, you can’t seriously mean-”

“The tryouts for Yuuei are coming up swiftly. I’ve already signed you all up for them.”

“What can we expect?” Yamamoto asked, relaxing once again. The only indication that he was still somewhat startled was how he tugged on his Necklace of Rain. Reborn began to gesture to his board.

“The test has two parts. One half of it is a practical portion. Yuuei is unclear on what exactly it contains form year to year but our sources indicate that it’s usually a point system implemented in different ways depending on the year.” Tsuna nodded - they could do that easy. He had confidence in Gokudera and Yamamoto’s ability and, after everything he's been through, confidence in his own.

“The other portion… is a written exam.” The blood immediately drained form Yamamoto’s and Tsuna’s face.

“Another easy one! We’ve got this in the bag Tenth!” Gokudera declared, even as Tsuna even as a single tear fell from Tsuna’s face.

“A wr-written test?”

“Of course Tsuna - it’s a school I don’t know what you’re expecting.”

“Isn’t there another way to get our hero license? Or can’t we just get in on a recommendation?” Tsuna asked desperately. Reborn let out a deep sigh.

“No, Tsuna.” He fired a warning shot past Tsuna’s head, ellicting a small shriek from Tsuna. “There may be other ways to attain a hero license, but this is the most logical way that’s not against the law. The added bonus is if you attend Yuuei it will help to teach you how to do hero work…” Reborn ground out the next word. “... _legally.”_

“And then there’s the next point - the Vongola can’t recommend you because we’re a group of Vigilantes, they’re diametrically opposed to us. They’d like our heads on figurative spits.”

“I see.” Gokudera nodded, a shadow falling over his face. “So we’ll also have to keep our connection to the Vongola hidden.”

“Correct. They’re are a lot of moving pieces here, but the chief among them is your secrecy. Meaning no calling Tsuna ‘Tenth’.” Gokudera shuddered. “As you know you’re flames aren’t quirks - they’re determination given a physical manifestation, but since you’ll be doing hero work with them we are going to update your files as if they are your quirks.” The three of them nodded. “It’ll be easy enough for Gokudera and Tsuna - it’s common for vigilante and mafia Families to refrain from giving away such information, so both of your will just need to apply for an update to your files. Yamamoto will be harder since you’re actual quirk is on the records - we already have some men working on it though.”

“Dad really never filled out my quirk form?” Tsuna thoughtfully put his hand on his chin. “That does explain some things.”

“It may be odd for three unrelated students to have the same quirk, but without a logical explanation they’ll have to accept it as fact, and while I highly doubt anyone on the school board is aware of flames, if anyone is they should be as keen to keep them a secret as the rest of us.” Reborn finished, cracking his knuckles and rolling his shoulders once. “...Any questions?”


	2. Exam

**Summary for the Chapter:**

> Tsuna and co take the UA exam

“Wow, this building is… huge.” Tsuna couldn’t help but to gawk as the three of them entered the testing area. It seemed like UA had more money than they knew what to do with. 

“I’m glad the written section is first, I don’t know how much longer I can hold this information in my head.” Yamamoto tapped his first against his temple. “I can basically feel it all rattling around in there.” Tsuna nodded in agreement. 

“This thing is going to be a peace of cake.” Gokudera replied, shoving his hands into his pockets. The test was given in a large auditorium like setting and the three of them quickly found seats near one another, wincing when the announcer bellowed the logistics. As the tests were handed out Tsuna felt his hands begin to shake as the doubts began creeping in. He was famously bad at tests, there was no way this was going to end well. 

Just as the anxiety began to creep up, threatening to choke him out, Tsuna felt the familiar reassurance as Yamamoto and Gokudera both gently pushed back against him. The tranquil rain and hectic storm harmonizing with his sky flames. Tsuna took a deep breath. So long as he didn’t lose his head,he would be fine. Gently he pushed back with his own flames to let his companions know that he had received their message before focusing back on the test. 

He could do this.

oOo

“Ahhhh, I just know I failed!” Tsuna muttered as the tests were taken back, and Yamamoto patted him on the back. 

“You did great Te- Tsuna, I know it!” Gokudera gave Tsuna a big smile as the lights for the center stage turned back on, the same announcer as before coming on. He began to break down the logistics of the second half of the exam. It seemed easy enough. Like Reborn had said it was a simple point based competition to see who could take down the most robots with the most points within the time limit. Gokudera pumped his fists. 

“Child’s play for us!” He exclaimed, and Tsuna tried to shush him as several of the people in their immediate vicinity gave them dirty looks.Gokudera lowered his voice. “Even without our Vongola Gear we’re going to blow away the competition.” Tsuna nodded. 

Their Vongola Gear had to be put into it’s hibernation/general use ring form until… well... they’d have to figure out when they could release their power later. The Vongola Gear was too flashy, and it had Decimo and Vongola insignia all over it. Even just the rings as they were were a risk, but one they would have to take. The only reason they were to use the Vongola Gear, until future notice, was in an extreme emergency, and with the knowledge that their chances to get their hero licences would be ended after that. 

The past few months had been spent training them all to use their flames not only without their gear or Cambio Forma, but Yamamoto had had to go without any swords and Gokudera without dynamite. It had been tough at the beginning since neither of them were familiar with official dying will states or fighting while only summoning their flames, using only themselves and occasionally their rings as mediums, but progress had been swift and promising.

“Ah, looks like we were all assigned to different exam areas.” Yamamoto frowned a little.

“What? How can I protect Tsuna then?”

“You shouldn’t be worried about protecting me anyway Gokudera - you just need to focus on getting enough points and getting into UA.” Tsuna replied. 

“You’re right, I will stake my life on my ability to dominate this trial!”

“Not quite what I meant either…” The three of them lingered around one another a little longer, reluctant to disperse. 

“Should we do that thing?” Yamamoto offered. “Like before the ring battles?” Tsuna’s face lit up. 

“Oh, Yeah! A quick team huddle!” 

“Heh, I guess it helped us then.” The three of them got into a small huddle, spreading their arms over each other.

“Go and do well!” Yamamoto yelled and the other two yelled back their agreement. They broke their huddle and gave each other various goodluck looks and smiles before heading to their designated areas. 

oOo

Tsuna nervously shifted his weight as he stood in the gaggle of other kids ready to prove themselves. They were really going through with this - after months of working on their skills it seemed almost unreal. He didn’t recognize any of the other kids around, which was to be expected, but still off putting. It seemed like since Reborn first came into his life he had always had at least one member of his Family with him - To go into something like this alone just didn’t feel right, and Tsuna felt a smattering of butterflies in his stomach decide to suddenly take flight.

“Okay, Go!” The doors to the fake city opened and immediately everyone surged forward. Tsuna felt their desperation running through the air as he struggled to stay upright. If he were to lose his footing he’d get trampled for sure. 

By the time Tsuna finally made it to the city all the nearby robots were already getting taken care of, each having three or four kids attacking them, competing for the finishing blow. Tsuna shook his head. 

“Time to focus.” He mumbled to himself, bringing his fist to his chest. He could channel his power through the Vongola ring, but he wasn’t allowed to light it up. He could sense the flame of his will ignite on his forehead, the gem of the Sky ring lighting up. Tsuna squashed down the instinct to ignite it, instead focusing the fire of his Dying Will onto his hands and feet. He’d have to fly to the farther areas of the city to find more opponents, but that was okay. The calmness of his Dying Will state took over, and he could feel the familiar rhythm of Yamamoto and Gokudera somewhere nearby, in another fake city, their flames distantly reaching out to him. Even the others like Ryohei and Chrome’s flames, despite the distance, seemed to be brushing up against his soul and whispering to him words of good luck. 

Tsuna blasted the ground at his feet, pouring his flames out of his hands, and headed further into the city.

 

“Those three young men…” In the judging and spectator room there were dozens of screen focused on all the different simulations. Off to the side there was the running tally for each kid, the rescue points next to their kill points. 

“Ah, so you noticed too.” Principle Nezu walked over to where several heroes had drawn their attention. Three screens close to one another showing three different boys. 

The smallest of the three had an orange flame quirk which he was using to fight one of the various bots of the stage, climbing around it before punching a hand surrounded in the strange flames through it, effectively destroying it. The orange boy glanced around to find a new target, the flame on his forehead growing larger before he headed off into another direction.

The second screen showed a silver haired boy whose hands had a red flame covering them, throwing pieces of the fire at the opponent like bullets, their heat eventually melting through the metal of the robot, exposing it’s softer internal working. After that he simply tossed another flame right into its’ wiring, heading to find a new opponent without even waiting and watching the bot slowly short circuit and stop working. 

Lastly there was a lanky boy who blocked an attack from a robot before it could hurt a fellow tester. His hands were awash in blue fire which he used in a slashing motion, leaving a line of flame on the robot. The boy paused, concentrating, before the fire wrapped around the entire robot, and while it didn’t appear to do any harm, the robot just simply stopped moving. 

“Do they all have the same quirk?” Midnight asked, taking a moment to look between the three of them. While only one of they had the crown of flames on his head, occasionally the other two would have a flame splutter.

“Not quite, although they do look very similar.” Nezu replied. “I have my suspicions about them, but it’s too soon to say.”

“Is it even normal for such similar quirks to manifest themselves? And all at the same time too.” Mic frowned slightly. “I mean they even seem to know each other - they were hanging out before the exam and all their papers were turned in together from the same location. But they have no blood relation.” 

“It’s more than unusual, it’s borderline impossible. Especially if they aren’t related.” Recovery Girl replied. “If they manage to pass the exam I suppose we’ll have a chance to get a better look at them.” The other heroes nodded, turning their attention back to the other screens. There were other extremely interesting students to keep an eye on after all.

All Might spared a glance at a nearby screen where one of the boys had moved to, red fire eating the inside of one of the robots. Oh, and he was smoking. Toshinori felt his non existent stomach churn at even just the thought. That poor youths health. Regardless they were formidable and prospective future students. 

‘ _ Come on Midoriya,’ _ All Might glanced at the scoreboard. ‘ _ You can do this’. _

oOo

“That was fun, huh?” Yamamoto slung his arms around Tsuna and Gokudera, smile bright even as his limbs ached. Gokudera shoved off his arm.

“It was easy if that’s what you meant.” He rolled his eyes before shifting over his attention. “How did you do Tsuna?”

“E-eh - I’m not sure? I felt really good about it but there were some really incredible kids there.” Yamamoto nodded his agreement.

“I saw this one girl whose hair was a plant! And she used it to tangle up the robots.” Yamamoto mimed the action and Gokudera huffed. 

“They were still no match for us. We got in for sure.” Gokudera huffed as he opened the doors to leave the exam building, allowing Tsuna to go out first. 

“I sure hope we di-”

“CONGRATULATIONS!!!” Tsuna was cut off by the familiar voice. Before he could turn and look at the person he was instantly brought to the ground by three small bodies. 

“Tsuna-nii you did it!” Fuuta, Lambo, and I-Pin were all dog piled on top of Tsuna, who was trying (in vain) to sit up.

“I can tell by the looks on your face - you did extremely well!” Ryohei patted Yamamoto and Gokudera on the back. 

“Good job Boss.” Chrome picked Lambo and I-Pin up off of Tsuna, giving them each a candy. 

“Ah, are you okay Tsuna? We tried to tell them not to rush onto you but they were so excited.” 

“K-Kyoko!” Tsuna took Kyoko’s hand as she helped him to his feet, Haru coming over and helping him get the gravel off the back of his hoodie. “Guys… I thought you were busy?” 

“We thought you’d like to have a little celebration for finishing the test.” Haru replied, smiling proudly. 

“Awww, thanks!” Yamamoto smiled as the small group began to make their back to Namimori. 

“I’m proud of you, Hayato.” Gokudera almost fell to the ground at the sight of his sister. They’d been trying to make progress on that but thus far it hadn’t been going anywhere. Yamamoto supported Gokudera as Bianchi put back on her goggle. “Ah, I’m sorry, I forgot about how silly my brother can be. Nevermind that, I made you all treats.” 

“Bianchi, there’s yellow smoke coming off of those cookies… I’d rather not…”

oOo

“So this is the list of the classes?” Aizawa peered over the paper.

“Yes, it took some deliberating but we finally finished out decisions.” Principle Nezu nodded triumphantly. 

“...These total up to be three more people than you said we’re going to be part of the hero course program.” 

“My, you noticed that quickly! Yes, two more students in your class and one extra student to class 1-B. I assume it won’t be a problem?” Aizawa didn’t reply for a moment, just glancing over the names.

“What’s the purpose of it?” It was uncommon, pretty much unheard of for UA to just… make an exception. 

“There are three students that I’d like to keep an eye on.” 

“Then why not just kick three other students out of the hero program?” Nezu frowned a little, looking at the three names at the end of the roll. 

“I feel, if my suspicions prove themselves to hold true, this will make the steps we have to take when the time comes much easier.”

**Notes for the Chapter:**

> thank you for reading!


	3. First Day

**Summary for the Chapter:**

> Tsuna and Yamamoto attend their first day of school at UA, Gokudera tries to deal with being so far from the Tenth

 

The day that the class lists came out for the students, the entire Sawada household knew. Maybe even the entirety of Namimori. If Tsuna hadn’t become adjusted to his irregular life he might’ve thought that the apocalypse was taking place, or maybe that aliens had finally landed on earth. He hadn’t even gone to check the mail yet. It was a week until classes started and more concrete information on schedules and such had been slowly filtering in. Tsuna still had preparations and training to take care of, but it was also a lazy summer wednesday. 

At least it had been until Gokudera stormed in, waves of anger rolling over him. Tsuna’s Hyper Intuition quickly shouted to either calm down the situation or run before something blows up. 

“This is ridiculous!” Gokudera shouted and Tsuna hurried down the stairs, snagging his gloves on the way down. Just in case. 

“What’s wrong?” Tsuna asked to Gokudera who was pacing through the kitchen, his hands twitching, continually patting his pockets. Gokudera jerked his head as Tsuna emerged from the stairwell and instantly slammed something down on the counter. 

“Tenth!” He gestured emphatically to the piece of paper. “Jyuudiame, look at this!” It took Tsuna a moment to register what he was looking at as he picked up the paper. 

“Oh, the class schedule came out.” 

“Keep looking.” As Tsuna scanned the page, Reborn entered the room, hopping up on the counter to peer at the paper as well. Distantly Tsuna wondered what Reborn would do when he was too big to get away with doing that kind of thing.

“I’m in class 1-A…. And so’s Yamamoto!” Tsuna smiled briefly before instantly dropping into a small frown. “Ah…”

“I’m in class 1-B! It’s an outrage! We should call the school and demand they fix it!” 

“Usually private schools like this are really picky about the number of students in classes.” Tsuna winced as Gokudera pounded the table. 

“Then I’ll trade places with the baseball idiot.” 

“I don’t think that-”

“You’re looking at this all wrong Gokudera.” Reborn inserted. “You three are going to be attending school surrounded by enemies of the Vongola, we need to spread out our resources. Someone has to be taking stock of who’s in the other Hero course class to make sure we can be prepared for any threats that may arise, and who’s more capable for that than Tsuna’s right hand man?” Gokudera perked up a bit.

“I suppose you’re right. I wouldn’t trust Yamamoto to be a good spy on his own.” He nodded to himself before turning to Tsuna and clapping a hand on his shoulder, giving him a thumbs up and a wide smile. “Count on me to neutralize any threats!” 

“N-no that’s not what I- OW!” Reborn slapped Tsuna across the face.

“Grape juice~ Grape juice~” Lambo strolled into the kitchen and grabbed a juice box, hopping up to look at the paper and see what was distracting everyone. “Gahaha, ‘dera’s in the second place class!” Gokudera twitched. 

“It’s not the second place class, there’s just two different classes for the grade.” 

“Then why is it class 1- _ B. _ For B rank.” Lambo laughed a little more to himself as he began to fold the paper into an airplane. 

“Why you-!” Gokudera pulled out some of his hidden dynamite. Lambo took that as his queue to run out of the room. “Get back here you dumb cow!” The pair ran out the front door, the sound of explosions following soon after. The door was still open when Yamamoto came through with his usual bright smile. 

“Hey Tsuna did you see? We’re in the same class!” 

oOo

“How,” Gokudera gritted out. “...do you still not know how to tie your tie?” Yamamoto let out a small laugh as he carefully followed Gokudera’s instructions, adjusting his tie to a comfortable level. “And more importantly why didn’t you ask for help before we got to the school?” Yamamoto just have a small laugh as he picked back up his shoulder bag.

The trio were standing outside of classroom 1-A, a few different students filtering into the room as they stood together off to the side. Tsuna was off to the side talking to Reborn one last time on the phone - not by choice. Apparently Reborn had some last minute advice and instructions to give Tsuna before they were tossed into the fray, whatever he had forgotten to tell him at breakfast this morning. 

Gokudera glanced over before stepping a little closer to Yamamoto, lowering his voice to ensure that Tsuna couldn’t hear. 

“Okay, listen here baseball idiot. I’m going to be keeping an eye on the other class but that leaves you to protect the Tenth. I…trust you.” It seemed like Gokudera had to force the words out. “But if  _ anything _ happens you need to protect him at all costs. If things go south get Tenth out of here.” He didn’t mean to but as he spoke a flicker flame illuminated on his assorted rings, the storm of his Vongola Ring spurting up before he forced it down. 

“Trust me,” Yamamoto raised his hand between the two of them, clenching it into a fist as blue fire sparked off of it. “...I’ll make sure he’s safe.” The fire died back down but the two held eye contact for a moment longer, their resolve continuing to burn in their eyes. 

“Okay.” Gokudera nodded, satisfied, and backed away. 

“....yeah….alright....okay, bye Reborn.” Tsuna pocketed his cellphone and turned back towards the other two. “Alright we’d better head into class before the bell rings!” Tsuna smiled brightly at his companions. 

“I’ll see you at lunch Tsuna.” 

“Have fun in your class Gokudera. Make new friends.” Tsuna encouraged, giving him a thumbs up. Gokudera smiled and walked down the hallways to the 1-B classroom.

“Shall we head in?” Yamamoto held open the door for Tsuna, giving him a nod. The room was already buzzing with activity as the pair entered. One kid was yelling at another for having their feet on the desk, a conversation which looked like it had been going on for a while now. 

“Let’s find some seats.” Tsuna followed Yamamoto to the back of the classroom where there were still some desks that had yet to be filled in. As the walked past the rows of fellow students Tsuna could feel the eyes of the other students on them. Some merely curious, others judging or sizing them up. It was somewhat unnerving, but not as bad as Vongola banquets or parties (particularly one’s like the New Years celebration where the others are trying to figure out if you have a good enough act and whether they should be trying to mess you up in order to win).

Yamamoto placed his bag on a seat and Tsuna took one to his right, trying to settle down before the class actually starts. Tsuna was abuzz with nervous energy, and he found himself fixing his tie and his uniform jacket, adjusting the ring on his finger - anything to keep his hands busy. 

“Hi, I’m Mina.” A girl sitting in the desk in front of Yamamoto turned around, and Tsuna’s eyes widened. Her skin and hair was a bright, almost alarming shade, or pink. She had two twirly yellow horns and her eyes were black with golden iris’. 

“Ah! Nice to meet you, I’m Yamamoto Takeshi!” Yamamoto gladly took her hand, shaking it with his usual enthusiasm. “This is Sawada Tsunayoshi.” Tsuna spluttered some form of greeting and Mina just giggled a little. 

“Hope ya don’t mind me butting in a little but my name’s Sero.” Tsuna shook the new guys hand, noticing that he had a really strong grip. 

“So are you guys excited or what?!” Mina threw her hands up in the air and Yamamoto copied the motion with a big smile. 

“Yeah this is going to be so much fun!” 

“I’m just glad I got in.” Sero smiled lightly, scratching the back of his head. “There were some really cool people at the exam I was really unsure.” Tsuna nodded in agreement. 

“Hm, what’s going on?” Most of the class had gotten out of their seats and were looking at… something, leaving the the room mostly silent. The four of them got up from their chairs and followed the other kids to the front.

“...Life is short kids, you’re all lacking in common sense.” At the front of the classroom as a man emerging from a… a sleeping bag? He was clothed in all black with a huge scarf wrapped around his neck and disheveled black hair. Dark bags sat under his eyes and he had a light scruff, not like on purpose it just looked like he’d been too lazy to shave.

“I’m your homeroom teacher, Aizawa Shouta, pleasure to meet you.” From the tone of his voice it didn’t sound like he thought it was much of a pleasure. “Head down to the locker rooms and get into your gym uniforms. We’re meeting on the P.E. grounds.”

oOo

“Alright Tsuna are you ready?!” Yamamoto was stretching, watching a few of the other kids complete the 50-meter dash. 

“I guess?” It had been a while since they’ve done this kind of thing, they missed a lot of days of school for the Vongola, usually including the boring fitness tests. It would be the first time he’d used his flames for it though, which did send a tremor of excitement and curiosity through him. 

“Ah, looks like you’re up soon.” The students were in two lines and going two at a time. It was a quick check to see who he’d be running with. He looked a little nervously at the fellow next to him and glanced at Yamamoto, who just gave him an encouraging pat on the back. 

“H-hi! I’m Sawada Tsunayoshi.” The kid across from him jumped a little, seeming to break out of how deep in thought he was. 

“Ah! I’m sorry! I’m Midoriya Izuku-”

“Alright next.” Aizawa called out and Tsuna instantly turned forward, feeling bad for cutting off the conversation. He’d just have to talk to Midoriya later. “Ready, GO!” Tsuna rapidly dipped down into Hyper Dying Will mode reaching for his flames and quickly lighting up his hands, distantly he could feel the flame on his forehead flicker to life. He placed his hands behind him and easily flew his way to the other side of the small track. Not even close to his fastest speed, but it would do for now. 

He dropped his hold on his flames and sat down hard on the ground, mind spinning lightly. Usually he tried not to go in and out of Hyper Dying Will mode so suddenly. He looked up in time to see Yamamoto finish up his own 50 meter dash. No flames, just the baseball players own athleticism. He helped Tsuna up and and leaned in close. 

“Sorry,” He whispered. “...if I was a sun I’d probably be able to help.” Tsuna just smiled and shook his head. 

“Don’t worry about it, it’s my own fault.” The next few trials followed the same vein, some more adjusted for Tsuna’s flames and some where using them just wasn’t worth it - like the grip strength test. Yamamoto took pure delight in getting to throw the baseball. That kid from earlier, Midoriya, had some kind of confrontation with Aizawa, resulting in - and this is what really threw the pair of a loop - the teacher stopping the kids own quirk. 

Almost immediately Yamamoto placed himself in front of Tsuna. He may not have had Hyper Intuition but he was Tsuna’s guardian and had seen enough to know when to trust his gut, and his gut was shouting at him that this man posed a threat to their plan. And more importantly, to Tsuna. He could feel his flames instinctually bubbling up. 

The rest of the little athletics test was easy, even if neither Yamamoto nor Tsuna were quite ‘top of the class’ material, neither of them were bottom of the class either. In fact Yamamoto even managed to get into the top 5. Yamamoto did his best to try and angle himself around Tsuna, keeping him out of the sight range of Aizawa. 

Shield Tsuna from danger - that was his number one priority. 

oOo

Gokudera against one of the pedestal things outside of UA, absentmindedly flicking his lighter. He was so itching for a smoke, but he had promised Tsuna that he’d get off of them and he’d be damned if he didn’t at least try. So that left chewing gum that didn’t sate his addiction and trying not to chew on the inside of his mouth. 

He watched the students filter out of the school, friends walking in groups or lines, the occasional loner all by themselves. Gokudera scanned the crowd as he tried to find the familiar mop of brown hair, or at least tried to pick out Yamamoto’s tall form. 

“Gokudera!” He jerked his head to see both of his companions running at him and couldn’t help the smile the broke out on his face.

“Tsuna, Yamamoto!” He gave them both a brief nod as he reached into his bag. 

“How was your day?” Tsuna asked and Gokudera withdrew a notebook.

“It was good - the information I got on class 1-B just today it truly indispensable. For instance-”

“No, how was your day?” Tsuna gently pushed down the sketchbook. Oh. Right. Sometimes he forgot that Tsuna genuinely cared for him as a friend, that he didn’t need to be constantly proving himself in order to not get kicked out of the Family. He placed the notebook back into his satchel. 

“What was the ceremony like?” Yamamoto asked.

“Did you ditch it baseball idiot?”

“Actually, uhhhh, kind of our entire class did. Our teacher is kind of… unconventional.” Gokudera raised his eyebrows as they began to walk to the bus stop. 

“Well first let me tell you about my class. So as soon as I walk through the door…”

**Notes for the Chapter:**

> hope you like it! :D 
> 
> thank you for reading!


	4. Trial of Battle (part 1)

**Summary for the Chapter:**

> Hero clothes and class interactions
> 
> I have some links at the bottom of the chapter for hero designs for the KHR characters

“Today we are going to be starting right off the bat with…. A Trial of Battle!” The classroom instantly began to buzz as the classmates talked excitedly to one another. A few seats away from Yamamoto and Tsuna, Midoriya was practically vibrating. From fear or anticipation, it was hard to tell. “Head down to the locker rooms and get changed into your hero outfits!” A side panel of the classroom opened up revealing rows of clothing packs with each students number on it. 

“Yes, sweet!!!” The red head shouted, pumping his fist into the air. Unlike Aizawa, All Might seemed to revel in their excitement, his smiling getting bigger (if that’s possible) as the students rushed to find their outfits.

“He’s nice.” Yamamoto said as the pair strolled to the shelves of clothing, waiting for some of the kids to grab theirs first. Tsuna nodded.

“All Might’s even nicer in person than I thought he’d be.” The two slowly made their way to their own numbers and grabbed their kits, heading down to the changing rooms. 

“Ah, wait up!” Midoriya ran up from behind them, waving his arms. “Sorry, I never got to fully introduce myself.” He stuck out his hand. “Midoriya Izuku.” 

“Ah, I’m Sawada Tsunayoshi, but my friends call me Tsuna.” Tsuna shook the boys hand. 

“- And I’m Yamamoto Takeshi!” Midoriya looked between the two for a moment. 

“You guys seem really close…”

“We came from the same school.” Yamamoto explained and Midoriya blinked before smiling.

“That’s so cool! I thought Kaachan and I were the only ones!” The three continued to make their way down to the locker room.

“Hey Yamamoto! Hey Tsuna!” Mina and Sero from yesterday hurried up from behind them. The small group made idle chit chat the rest of the way, which Yamamoto was glad for. He’d prefer it if they could avoid how well he and Tsuna knew one another - it only took so many coincidences to stack up before things became fishy. 

“You guys are going to love my outfit! I based it off of those poisonous tropical frogs.” Mina wiggled her fingers and drops of acid dripped onto the floor as if to emphasize her point.

“Oh yeah, I almost forgot that we got to choose the designs.” Sero squinted at his package. “Did past me choose wisely? I guess we’re about to find out!”

They waved Mina goodbye as they reached the locker rooms, the boys heading over to get changed. 

“Is that one yours, Midoriya?” Tsuna asked as they found themselves a spot to change and lockers to use. A quick glance showed that some of the students were having a harder time figuring out how to actually put on their outfits. Iida was struggling with some of the clasps of his armor and further down the aisle Kirishima looked like he was trying to remember how he had designed the circular shoulder pads to fit on without falling off. 

“W-well you see, my, um, my mom made me mine.” He was profusely blushing, but Tsuna just smiled. 

“That’s awesome! My tutor is working on one for me too, he’s just not done yet.” Midoriya beamed at that, proudly pulling out a bright green outfit. 

Yamamoto and Tsuna quickly began to get changed into their own clothes. It was true that Reborn was working on an outfit for Tsuna, but he was also working on one for Yamamoto and Gokudera. They weren’t sure if the school’s ‘fire proof’ was the same as theirs, and there were some things you just couldn’t request on the outfit sheet. Specialized things like Vongola comm units, dynamite storage pockets, different types of adjustments that could only be made my someone like Reborn or Spanner - those who knew their real abilities and could plan accordingly. 

“Tsuna! Who gave you that?” Tsuna glanced at the shirt he had just taken off.

“Uhhhhh, my mom?” Sero widened his eyes at that, sucking in a sharp breath. Off to the side he could see Yamamoto shaking his head slightly, pointing to his back. Tsuna frowned - what was Yamamoto talking about?

“Tsuna’s dad is a really low profile hero. It’s just from a mishap during a mission they were on that Tsuna got dragged into.” 

“O-oh, that’s…” Midoriya was worriedly looking at his back. “...that’s a nasty scar.” Tsuna frowned - plenty of the other kids had scars too, small knicks and stuff that littered their bodies. Nothing extreme as they were still young, but Tsuna having a few shouldn’t stand out too much.

“It was fine. Luckily we have a friend with a healing quirk who helped us out.” Yamamoto waved off. Tsuna continued trying to go through injuries he had on his back. Maybe… Oh. The huge X scar from Genkishi in the future. It was easy to forget when he couldn’t see it. It stretched from each shoulder to the opposite hip, the long and precise lines that were a memento of a time wreathed in dark shadows of memories. 

“That’s wicked.” Kirishima had come over and was looking at it in almost… envy? It looked like he’d finally gotten his hero outfit figured out. 

“Tsuna you should get dressed - I’m excited to see what your hero outfit is.” Yamamoto graciously changed the subject, moving so that he was blocking Tsuna’s back from the majority of the other students. The small crowd dispersed, either leaving the locker room or getting around to changing their clothes. 

Yamamoto waited until they were mostly alone to take off his own shirt, revealing his own lines of scars and burn marks. Nothing quite as ostentatious as Tsuna’s but still just as many. 

They had designed their own outfits of course, with the help of the rest of the Family. Haru in particular had enjoyed helping them come up with unique ideas, even going so far as to make cheap examples they could try out. 

Tsuna’s outfit was a bit of a callback to his time in the future with Spanner, a jumpsuit with a zipper down the front. He didn’t zip it up all the way, and you could see his orange tank top peeking out a bit. The sleeves only went halfway down his arms, ending in elbow pads. The pant legs were full length along with knee pads. He had a pair of sturdy boots with holes in the top of them for some ventilation. For his hands he had fingerless gloves with a hole cut into the top of them The jumpsuit itself was a dark charcoal gray, almost black, the only color being lines on the outside of the arms that were a bright orange. Lastly he had two criss crossing ‘belts’ that were actually dense rope that was layered over a few times. You never knew when you’d need some rope.

Yamamoto based his around his Cambio Forma, specifically the top half looking almost identical with the loose shirt that crossed over itself and loose sleeves. Similar to Tsuna, they ended in elbow pads. He had a black sleeveless undershirt, the collar of which was low and straight from one side to the other. The top ended with a wide black belt, which had places to put sheaths for swords, but were empty for now. He had loose pants as well that ended in knee pads. He forewent the traditional shoes for more modern, lightweight boots. The entire outfit followed the white, light blue, navy, and black color scheme that his cambio forma had. On the back of the shirt was embroidered a bouquet of flowers in white along with the kanji for dog and bird on the left and right respectively. 

“It turned out really good!” Yamamoto commented as they headed to the training room 8-C. Tsuna nodded and adjusted his gloves. 

“Yeah, they made it out of really breathable fabric too. I just hope it’s durable.” The rest of the class was clustered outside of the training room, everyone looking at each others outfits with excitement. The doors to the training room opened slowly and dramatically, light filling the dark tunnel.

“Let’s see what you’re made of…” All Might’s voice boomed around them, reverberating off the walls. “...it’s time for your battle trials!” Tsuna openly gaped at the entire city reconstruction in front of them. He had expected an indoor training ground but instead it was all open air, buildings going as far as he could see from his current vantage point. 

“You all look amazing! Very Cool!” All Might gave them all a thumbs up. It was kind of incredible to see how much the entire class seemed to glow just at the simple compliment. All Might truly was a pillar, undoubtedly someone that most of them had looked up to their entire lives. Being in the same room as him was probably like a dream come true for most of the kids here, if not all of them.

Neither him, Yamamoto, or even Gokudera had really grown up with the same idolization. Sure Tsuna thought he was cool, but not like these kids. He had never wanted to  _ become _ like All Might. And up until recently, any kind of hope like that had seemed to be getting farther and farther out of his reach the further he got into the mafia.

Still, Tsuna couldn’t help but to blush lightly and straighten out the front of his uniform as All Might continued to point out specific details he liked in several of the kids costumes. 

“Sensei! Why are we using the mock city from the entrance exam?” It took Tsuna a second to recognize the student asking the question as Iida. His bulky armor had completely covered him up and his voice coming through the helmet was slightly muffled. 

“Ah, you see, take two steps forward you’re at our training grounds for today - this will be an indoor battle!” Tsuna frowned - he was definitely better with more spacious area - unless he had a gun. He had a feeling All Might wasn’t going to let them shoot each other with guns though. “Usually villain fights are seen out in the open but in reality the majority of hero work happens indoors - and I don’t just mean paperwork!” 

“Imprisonment… house arrest… the black market… truly any sensible villain lurks in the shadows.” Tsuna sweated slightly - all of those things were things that the Vongola were a part of. He shook himself a little. That’s why he was here, so that he didn’t have to take part in that Vigilante world. “For this test, you’ll separate into ‘Hero’ and ‘Villain’ groups for a two-on-two team battle!”

Instantly different students began to make eye contact with one another, some pointing, a few even flat out yelling who they had dibs on to be in their group. Yamamoto put his arm around Tsuna’s shoulders. Several of the students began shouting questions and All Might held out his hands in a ‘hold on’ gesture.

“Don’t all talk at once, I can’t understand you.” He reached into a pocket on his uniform and withdrew an almost comically small piece of paper. All Might launched into a small explanation of the battles, including how the teams would be setup as ‘villains’ and ‘heroes’. The idea is that the villains are in charge of guarding a fake nuclear weapon while the heroes have to try and separate the villains from the fake nuclear bomb and obtain it. Either side could win if they detain the entirety of the other team. 

“Teams will be picked by drawing lots!” There were various groans from the students and Yamamoto’s hand on Tsuna tightened ever so slightly. Tsuna responded by reaching up and touching his hand, slipping some sky flames into his palm. “Now now, often times in hero work you end up working with new people all the time! I will also need two people who are willing to go twice in order to balance out the team numbers.” 

“I will do it!” Iida shot his hand into the air, eyes intense. He had taken off his helmet at some point - probably a good idea. 

“I can go twice.” The other person was one of the girls. She had long black hair and a...pretty revealing hero outfit. 

“Excellent! Now please, pick your teams!” All Might placed down a box and quickly the kids stepped forward, drawing letters. Tsuna looked at his letter and glanced up, trying to find his partner. Yamamoto had already found his own partner - Iida - and was making idle chit chat with him. Bakugo, Iida’s other partner, was ignoring them by stalking off somewhere. 

“Sawada.” Tsuna turned around to see the girl from earlier walking towards him. “It looks like we’ll be partners today.” 

“Ah! It’s a pleasure to meet you…”

“Yaoyorozu Momo.” He gave her a small nod. “You’re quirk was quite interesting to watch yesterday, I look forward to collaborating with you.” Tsuna blushed lightly.

“Oh, uh, thank you.”

“It’s safe to assume you’ll be more pleasant to work with than my other partner at least.” Tsuna frowned. 

“Who’s your other partner?” Yaoyorozu just pointed behind herself. Ah. It was the small classmate with the purple hair. 

“Alright! Teams A and D are going first - the rest of you make your way up to the observation room!” 

**Notes for the Chapter:**

> Thank you for reading!
> 
> I did some quick mock ups of the hero designs for the Khr characters:
> 
> http://the-east-art.tumblr.com/post/175341449975/hero-outfit-concepts-for-tsuna-takeshi-and


	5. Trial of Battle (Part 2)

**Summary for the Chapter:**

> Yamamoto fights with varying degress of control

The first battle was the most intense. Midoriya, Uraraka, and Bakugo had to get taken to the nurses office afterwards and the rest of the spars had to set up the entire thing in a new building. Luckily there were several identical buildings in the model town so all they really had to do was move the fake nuclear weapon. There wasn’t any noise for the battles since no speakers were installed in the building, just cameras, so most of the students had taken up talking over the battles and turning them into TV dramas. 

     “Honey, do you like the dinner I prepared?” Kaminari voiced over Sero.

     “I-it’s great.” Ojiro replied in place of Kirishima. He placed a hand over his mouth to muffle the next part. “I hope he doesn’t find out about my affair...with a frog!” Ojiro gestured to one of the screens that showed Tsuyu. 

     “He’s such a good husband.” Kaminari continued as Sero set out into the rest of the building to try and stop the ‘heroes’ before they got to the weapon room. “...as long as he doesn’t meet my emo bird ex things should be fine.”

    “Dun Dun Dunnnn” Sero ran into Tokoyami in the hallway and they prepared for a showdown.

     “Come back babe I miss you.” Sato replied for Tokoyami. 

     “No! You maybe me listen to nothing but My Chemical Romance for three weeks!”

     “It was the anniversary of their breakup!” 

     “Please,” Iida shouted. “...pay attention to this learning activity. Think of all the skills you could gain with a watchful eye!” He reprimanded the class, and it might have worked if All Might hadn’t joined in soon after that, loud booming laughter accompanying the fake soap opera. 

     Eventually the battle ended with Tokoyami and Tsuyu winning, and All Might ushered Yamamoto and Iida to the prep area as the ‘villains’ while their opponents - Jiro and Kaminari - got their debriefing outside the building. By the time they got to the floor where the fake missile had been moved to the place had been mostly cleaned up and most evidence that Sero had been taping up the entire place was gone. 

     “In order to work out a strategy I need to know what your quirk is.” Iida turned to face Yamamoto. “Mine is pretty obvious.” He gestured to his engine’s and Yamamoto nodded.

     “I don’t remember what mine is called exactly, but this is it.” He took a deep breath and closed his eyes and just  _ felt _ for his flames. There they were, just quietly crackling under his skin. He pulled up on them and they ignited his hands. Iida was staring at them with a clear focused intent. “You can touch them if you want.”

     “Incredible.” Iida had his hands over the twin blue flares. “It’s cool to the touch.” Yamamoto nodded.

     “They can burn things, if I want them too, but they also have other properties.” He extinguished them. “It’s probably best if you didn’t touch them too much. I was thinking we could set up a barrier around the room in my fire and then I can go out and set areas of the hallways on fire.” 

     “Okay, but try to be quick - I’d like to also do some rounds of the hallways when you get back. All Might purposefully didn’t tell us when they’d be entering the building so we have to be careful and quick.” Yamamoto flashed a thumbs up. 

     “I’m on it.” He quickly traced the perimeter of the room and a tight circle around the fake warhead in blue fire before heading out to the rest of the building. In theory the fire should only die down if he wanted it to or if he died. But he  _ was _ still getting a hang of using the dying will flames like this so he wouldn’t really be surprised if they ended up going out at some point.

     He just focused on running down the hallways and spreading around the fire, hoping that it would be enough of a defense and a distraction. Yamamoto wiped his forehead. That was a lot of Dying Will Flames in very little time. He should head back to the base room and let Iida do the running around for a bit. 

     “That’s a neat trick.” Yamamoto jerked around to see Kaminari emerging from one of the side rooms. Instinctively he began to pour his will into his ring before jerking it back out. His hand twitched towards his side. But no, he couldn’t activate his Cambio Forma and he didn’t have a sword on him. 

     He was just a little out of his element. 

     “I have a few more.” The blue fire flared back up and Kaminari was forced into the middle of the hallway. Kaminari’s hands sparked with energy and Yamamoto took deep breaths. When Kaminari lunged forward (in a clear attack, easy to read) Yamamoto dodged to the side. The electricity crackled and Yamamoto’s breath caught in his throat. He slashed with his hand, hitting Kaminari in the gut and sending the boy crashing to the ground. 

     “Sorry.” Yamamoto muttered under his breath as he reached for the rope that had been supplied to them. 

     “Me too.” Kaminari grabbed Yamamoto’s leg and and energy crackled through his body.

     It didn’t hurt that much. Kaminari was a young boy with a young quirk. But that feeling,  the electricity coursing through his body, how it tingled under his skin, the sizzle and burn. It sent Yamamoto back, back to a man surrounded by green crackling electricity. It couldn’t have been long, only a brief moment that Yamamoto let himself be consumed by the memory, but it was enough for Kaminari to jump up and start running down the hall. 

     “No!” Yamamoto lurched forward and the fires blazed up, enveloping Kaminari. Surrounding the boys body before vanishing. Carefully Yamamoto crept forward, looking at Kaminari. No burns, good, and the boys’ chest was moving up and down rhythmically. Yamamoto smiled - the tranquility of his flames had worked. 

     For now he had to get back to Iida. 

     Yamamoto pulled his flames back. The last thing he wanted was for them to accidentally burn Kaminari. He paused for a moment to take a breather - manipulating his flames this much, pouring them all over the place, was a lot harder than he anticipated. He felt the beginning of a kind of bone deep ache he hadn’t felt since probably his trip to the future. They’d have to focus their training more on this kind of thing. 

     Turning around he started back to the base room, leaving a majority of the flames where they were. He wasn’t sure where Jiro was at this point, but on the off chance that she was somewhere nearby at least the tranquility of the flames would help to slow her down. Yamamoto turned into the room to find Iida pacing around nervously. 

     “Sorry it took me so long!” 

     “What happened? Did you run into trouble?” Iida had taken off his helmet by now, and Yamamoto took one look at his half lidded eyes and internally berated himself. He must’ve let his control of his flames falter during the fight with Kaminari. He quickly extinguished the majority of the flames except for a line guarding the doorway and the circle around the fake missile. 

     “I had a run in with Kaminari, but I knocked him out. If we’re lucky it’ll last long enough to deal with Jiro.”  

Iida nodded and hurried off, hesitating slightly before the rain flames. Yamamoto gave him an encouraging thumbs up and his partner took off into the building, heading in the opposite direction from where Yamamoto had been. Yamamoto did his best to keep himself from getting bored by playing with his allotment of rope, quizzing himself quietly on different knot types. Eventually he grew tired of that and just began to nervously touch the sides of uniform where his swords would usually lie.

Yamamoto quickly jerked around as his senses flared up, just in time to see Jirou standing in front of the flames, looking at them nervously. As soon as she noticed that he had spotted her she put her fists up. He responded in turn by lighting his hands on fire.

Now, Yamamoto had been through many fights with many different kind of baddies involved, all with their own techniques. To say that he hadn’t expected her earlobes to move down and attach to speakers would be an understatement. The shockwave Jiro sent out pushed Yamamoto backwards and he felt with grip on his flames (which was a work in progress in the first place) slide, leaving the entrance completely unblocked. Jiro came in quickly, taking advantage of his moment of weakness. She rushed forward and darted towards the fake nuclear warhead. Yamamoto recovered and leapt up, blocking her path.

Jiro punched him in the jaw. Yamamoto tasted blood and grinned wider. He grabbed her hand and threw her across  the room. Well, half the room. He was trying to be gentle.

“Nice moves.” Jiro raced forward and kicked out, Yamamoto hopping up and landing a fire lit palm on her leg before vaulting out of the way.

“Thank you!” Yamamoto replied before slashing in front of Jiro when she tried to make more progress towards the missile.

“Now Kaminari!” She shouted and Yamamoto looked up in alarm to see that indeed, Kaminari was awake and in the doorway. Internally he berated himself for not noticing in the first place (Reborn and Squalo would never let him hear the end of it when they found out). Jiro grabbed Yamamoto by the shoulders and swung him around as Kaminari let loose a huge, scattered shot of electricity into the room.

Yamamoto felt his muscles seize as the electricity coursed through his body, taking him to another time and place. He made an attempt to make his arms and legs obey him, but they remained resolutely spasming underneath him. Desperately as he felt more than saw someone move in the corner of his eye he reached for his flames, hoping that their calming effect could manage to persuade his limbs into working order. Yamamoto gripped the core of fire yanked on it, harshly and almost painfully.

The world around him faded to a murky black abyss.

oOo

Yamamoto’s eyes jerk open to be assaulted with the smells of antibacterial disinfectants and lying in sheets unfamiliar to him.

“Ah, you’re awake dearie.” Yamamoto blearily sat up, rubbing the sleep from his eyes. It took little effort to realize he was in the school’s infirmary, the recent events quickly coming to the forefront of his mind. He looked at his bedside to see Recovery Girl, one of the heroes they had done research on before starting at UA. He gave her the best bow he could manage while sitting in a bed.

“Thank you for taking care of me.”

“It is a relief to see that you are okay.” Iida was sitting next to Yamamoto’s bed, back in his school uniform.

“Ah, Iida, are you okay?” Yamamoto asked, recalling the boys absence.

“I am sorry I let you down Yamamoto, Kaminari snuck up on me and sent an electric burst through my engines, causing them to fail for a while.” Yamamoto waved him off.

“I’m just sorry you lost again.” Iida shook his head, a small smile just ghosting his face. “We won?” Yamamoto asked, raising his eyebrows. Iida shook his head again.

“According to the others before you blacked out, while Kaminari and Jiro were heading towards the fake missile, your flames suddenly flared up. It knocked them both out and gave them a few burns but since it meant that both teams were incapacitated, it was a stalemate.“

“Are they-“

“They’re fine dear, you just missed them. It was nothing I couldn’t fix up quick. You just may want to be more careful with that quirk of yours in the future.” Recovery Girl patted Yamamoto’s knee and he relaxed a little more. “Iida dear you should head back to class. I still have some tests to run on Yamamoto here now that he’s up.”

“Yes maam, thank you for letting me stay with him to make sure he was okay.” Iida gave a small bow to Recovery Girl before turning to Yamamoto. “I will see you soon.” He took off after that, and Recovery Girl gave a small huff.

“So full of energy, these young kids.” She stood up and motioned for Yamamoto to follow. “I just want to make sure everything is fine after that electric surge you got caught in.” Yamamoto nodded and Recovery girl sat him down before pulling out her stethoscope. “Take your shirt off for me.”

Chiyo Shuzenji had seen a lot in her time. Somehow none of it had quite prepared her for what she saw next. The boys back, his arms, torso… all of it was engraved with scars. Lines that stretched across his body, the pucker of ones that had been stitched back together. There was the tell tale melted look of burn scars and dramatic lines from electricity, too old to have been from today’s events.But the boy tensed when she paused so instead she didn’t mention them, pushing through and gently, slowly, placing the end of the stethoscope to his back. 

“Take some deep breaths for me dear.” His heart was doing just fine, which was a relief. Sometimes electric shocks could ruin the rhythm but his was just pumping away fine.

“You heal, right?” The boy asked as Chiyo wrote a few things down on her clipboard.

“Yes I do.”

“ I was wondering if you could help a friend of mine out…” Chiyo heard Yamamoto state the case for his friend, and felt her eyebrows raise. She didn’t usually take on students, but this… this could be very interesting.

**Notes for the Chapter:**

> sorry it's been a while - and it will probably be a while until the next chapter, but I assure you I'm working on it :D
> 
> thank you for reading, I hope you are having a lovely day!


	6. Trial of Battle Part 3

**Summary for the Chapter:**

> Tsuna and Yaoyorozu finally get their chance to try out the battle trial

Tsuna fidgeted as he eyed the tall building in front of them, comparing it to the map. Yaoyorozu was currently discussing their plan, but Tsuna found himself continually nervously looking up. Their plan hinged on him being able to do this.

“If it’s too much I can make a ladder for you.” Yaoyorozu offered, and once again Tsuna took note on how she held her body close, as if trying to cover herself with her arms.

“N-no, it’s okay. I think I can make it?” The starting bell rang out through the area and Yaoyorozu folded up the map and put it back down.

“Okay, I’ll see you inside.” She circled around the building to go in through one of the back windows and Tsuna took a deep breath, taking a moment to compose himself. He gently pulled on his flames, igniting the flame on his forehead and engaging Hyper Dying Will Mode. It still wasn’t perfect yet, but it would have to do for now. He lit up his hands and poured them underneath them, launching himself to the top of the building and bursting through one of the top story windows.

Yaoyorozu would start from the bottom and he’d start from the top.

Tsuna shook his hands, wincing slightly. Luckily it was just a quick jump up here – he was still struggling to keep his flames harmonized to his skin, resulting in numerous burns and blisters on his hands. When they had been training with Reborn they’d just had Ryohei heal his hands (Reborn refused to – he called making Ryohei do it twice the training for the price of one) but he still had to at least finish this battle trial thing before he could get his hands taken care of. He just had to be careful is all.

After getting his bearings a bit Tsuna began to go through the rooms systematically. After two floors of empty rooms Tsuna’s patience began to wear thin. At this rate Yaoyorozu could have run into them and already be fighting others, in need of Tsuna’s backup.

He stopped in the middle of the hallway letting his hands rest at his side and closing his eyes in concentration. Instinctively his senses jumped out to look for his guardians, following the familiar paths to see that – Chrome is okay, flames are burning as brightly as ever, no concern there – Hibari is also nominal, the brief flicker letting Tsuna know he was probably picking a fight with someone right now-

Tsuna jerked himself out of his habitual check in routine, jarring himself somewhat in the process. He took a few more deep breaths and focused back in again, instead spreading his senses slowly farther and farther out from himself. About two floors down he sensed the small sliver of a sun flame (the kind of small flicker of fire that people who hadn’t activated their flames had). Farther than that was a flicker of storm flames. Finally, farther down, probably on the second floor, was the smallest idea of a cloud flame – Yaoyorozu, his intuition supplied, recognizing the signature of the flame.

He took a second to readjust his senses after sending them out like that, shaking his head a little before hurrying down the stairs, following the soft heartbeat of the sun flame he had felt.

oOo

“Wow, Tsuna’s really talented!” Uraraka said in awe as the teens looked at the screens. Tsuna had burst into the missile room so fast that the screens couldn’t track the movement, the next second revealing him finishing tying up Aoyuma. All Might had been looking at the screen with rapt attention. In another screen Yaoyorozu was having a showdown with Mina. Yamamoto still hadn’t come back yet, but the other three from the last battle had returned and assured them that the boy was fine.

           “How does his quirk work? Does it come from his body? Does he emit flammable gas? What about the tracking thing he did earlier – can he sense body heat on top of all of that? That’s not to mention how similar the fire seems to behave to Yama-“

           “You’re really curious about his quirk.” Uraraka cut in and Izuku jumped slightly, getting suddenly pulled from his concentration.

           “Ah! W-well, yeah. At first I thought it was like Endeavor’s quirk, but the longer I see it in action the stranger it is.”

           “I just think it’s neat.” She replied, a small smile playing on her face.

           “Of course it is.” Both of then flinched at the sudden, unfamiliar voice, turning quickly to see who it was. “Tsuna’s the best.”

           It was a kid that neither of them recognized, definitely not one of their classmates. He wore the UA uniform, but the sleeves were pushed up and he had several wristbands and bracelets decorating his hands and a multitude of rings on his fingers. The kid had silver hair with long bangs parted in the middle, the rest of his hair spiky and unorganized looking. Izuku managed to catch sight of several ear piercings as well. He had a simple choker necklace on and was looking at the screens with a look of, well, absolute admiration.

           “Excuse me this is a class 1-A training exercise, I must insist that since you are not a member of class 1-A you leave immediately.” Iida was frowning at the boy and doing his choppy hand motion thing. The boy just rolled his eyes.

           “I don’t take orders from you.” He chewed on a toothpick, sizing Iida up for a moment before seeming to completely ignore him, turning away from the boy. On the screens Tsuna came down to help Yaoyorozu out as the two of them took care of the Mina, wrapping her up in rope before high fiving each other. The strange student nodded, a bright smile on his face.

           The door to the surveillance room opened behind them and Izuku quickly looked back, wondering if another strange student would be coming in. Instead he recognized the silhouette of Yamamoto, who he was relieved to see was looking fine despite having been shocked with who knew how many volts of electricity.

           “Shoot, did I miss Tsuna’s battle?” Yamamoto asked as he Tsuna and Yaoyorozu begin untying the others.

           “Of course you did, idiot.” The strange student retorted.

“Gokduera! “ Izuku found himself raising his eyebrows. So they knew each other. “Shouldn’t you be in class right now?” Yamamoto swung his arm over Gokudera’s shoulders, who made a weak attempt to shrug it off but seemed resigned to his fate.

“I could pass English even if I was deaf and blind.” Gokudera rolled his eyes.

“Since Tsuna just finished up we should meet him down at the nurses office – He’s going to be so excited to see you!” The pair walked back out the door, leaving the rest of the class just kind of staring at their retreating backs.

“So he knows Tsuna too?”Uraraka questioned, and Izuku frowned slightly.

“It looks like it.” Izuku glanced up to see even All Might seemed deep in thought. He thought for a moment about Yamamoto’s blue fire quirk, about the orange flames that had come off of Tsuna… “I wonder what his quirk is.”

“Your quirk is really incredible Yaoyorozu!” Tsuna cheered as the pair walked to the nurses office with Aoyuma and Mina. All teams were required to get at least a look over after their battle’s to ensure that they were all in good health. Tsuna put up his hand for a high five before slowly retreating it back down. Probably best not to high five with the burns he was currently sporting on his palm.

“Thank you Sawada.” Yaoyorozu replied with a small nod of her head in Tsuna’s direction. Her arms are wrapped around her waist again.

“Yaoyorozu… are you uncomfortable with your hero outfit?” she jumped a little at that, and he saw a red blush begin to creep its way onto her face.

“I- n-no.” Her arms tightened around her waist more. “Well yes, but I did design it after all. I just thought that all the bare skin would be practical. In theory.” Yaoyorozu bit her lip, looking at the ground. “I guess I didn’t take into account how I’d feel in it. But-“ And she looked up with determination and… and a little fear? “If I can’t get accustomed to something as normal as clothes how can I expect to become a hero? I figure that I just need to wear it enough to get used to it.” Her blush had only gotten worse as she talked. Tsuna shook his head.

“If you like it I’m not going to tell you to change it, but if you’re not comfortable in it then won’t it just distract you from hero work?” She frowned. “I have a sister who used to wear short skirts a lot so we just assumed she liked to fight in them. But later she told us that she was more comfortable fighting in more practical clothes. Like pants. And she knew that her comfort was what would help her have confidence in a battle.” Yaoyorozu nodded along, glanced down at her own hero costume.

“That makes sense.”

“Here, what’s your number?” Tsuna pulled out his phone. “Let me send you contact information for a friend of mine. She’s the one that helped me and Yamamoto with our costume designs – she’s super creative and good at thinking outside of the box for costume designs. I’m sure with her help you can find an outfit that fits what you want without sacrificing your confidence.” He sent Haru’s contact information over to Yaoyorozu.

“Thank you.” She smiled and added the number to her contacts. The pair entered the infirmary.

Mina and Aoyuma had been ahead of them and were already getting looked at by Recovery Girl, who seemed to just treat the wounds normally if it would heal quickly on it’s own, so Aoyuma was placing ice on a budding bruise on his ribs. Tsuna winced a little when he saw it – maybe he had gone a little too hard on the boy. But from the sparkles he was giving off he didn’t seem bothered by it, in fact he waved when he saw Tsuna enter the room.

What Tsuna definitely hadn’t been expecting was to see two of his guardians waiting for him. 

“G-Gokudera! Don’t you have class?” Gokudera just waved his concerns off, rushing over and clapping Tsuna on the back. 

“Great job Tsuna! You did great!” 

“A-ah. You saw all that?” Tsuna stammered. 

“Alright, let me through dear.” Recovery Girl parted the crowd of two, having seen to Yaoyorozu. “Please have a seat.” She gestured to one of the beds and Tsuna obediently sat down, Yamamoto and Gokudera both sitting down on an adjacent bed. “Now what trouble did you get to?” Tsuna immediately offered his hands, angry red palms up. 

“Te-Tsuna!” Gokudera exclaimed, and Yamamoto looked at him with that concerned look of his. 

“I-it’s really no big deal. I just need to get better.” Neither of the two seemed pleased with that but regardless they let Recovery Girl do her job and heal up his hands. 

“Be more careful in the future.” She gave his hands a gentle pat and offered him a lollipop. Tsuna gave Recovery Girl an obedient nod, feeling a small of fatigue come over him. Almost immediately it was followed by a push of flame from Gokudera and Yamamoto, which just made him roll his eyes, but he accepted it anyway, already feeling more awake. 

“Lunch is next class period, right? Let’s go out!” Yamamoto insisted with a big smile on his face. 

“Let’s finish this class first.” 

 

oOo

 

All Might watched as young Sawada and Yamamoto came back, their third companion in tow. The other boy. He did his best not to let his gaze linger on them too long, especially when he had done it earlier and Sawada had almost immediately turned to meet his eyes. He thought back to the flames he had seen two of the boys use, carefully keeping the bright smile on his face. It was indeed like Principle Nezu had said. The evidence was there. 

He was one of the few privy to the knowledge of what the boys were, having come in contact with their kind before. Just him and an extremely small handful of the teachers. He spared them another glance, the three of them were hovering around one another in that unconscious way close friends do. 

All Might knew what they were, but they were also here, to become heroes. 

 

How badly he wanted to give them the benefit of the doubt. 

**Notes for the Chapter:**

> (me, giving Yaoyorozu and Chrome decent clothes, shouting loudly) IN THIS HOUSE WE DONT SEXUALIZE TEENAGERS
> 
> anyway thanks for reading! sorry for the absence - I Was overseas with no computer   
> I hope you're having a lovely day!

**Author's Note:**

> Welp I've had this on my mind for a while! So in this fic basically Flames and Quirks are two separate things - something I'm hoping to expand on in the future! I hope that this was a good set up for what I hope is to come :D 
> 
> Also just a heads up I have no intention of letting the KHR kiddos be too OP or anything, I'm hope jsut to write a good balanced story and have fun with both casts of characters :)
> 
> Thank you for reading!


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